High metal content complex salts of sulfonic acids and mineral oil compositions thereof



HIGH METAL CONTENT ODMPLEX SALTS OF SULFONIC ACES AND MiNERAiL 91L COMPO- SITIUNS THEREQF Herbert Myers, Haddonfield, and Ferdinand P. Otto,

Woodbury, N. 3., assignors to Socony Mobil Oil Comparty, Inc, a corporation of New York No Drawing. Application September 4, 1952, Serial No. 307,923

22 Claims. (Ci. 252-33) This invention relates to improved lubricating oil compositions for use in internal combustion engines. More particularly, it relates to a new class of detergent additives for such lubricating oils and to a method for their preparation.

It is well known that lubricating oils tend to deteriorate under the conditions of use in present day diesel and automotive engines with attendant formation of sludge, lacq'uer and resinous materials which adhere to the engine parts, particularly the piston ring grooves and skirts, thereby lowering the operating efliciency of the engine. To counteract the formation of these deposits, certain chemical additives have been found which when added to lubricating oils have the ability to keep the depositforming materials suspended in the oil, so that the engine is kept clean and in etficient operating condition for extended periods of time. These addition agents are known in the art as detergents or dispersants. Metal organic compounds are particularly useful in this respect. These metal organic compounds are considered to be elfective on the basis of their metal contents, coupled with their solubility in the oil. Generally, it has been found that the oil-soluble metal organic compounds having the greater percentages of metal provide the better detergents. On this basis, it has been sought to provide detergent compounds having the highest possible metal content. Metal sulfonates, such as metal petroleum sulfonates, obtained by the sulfonation of petroleum oils and synthetic sulfonates obtained by the sulfonation of wax aryl com pounds, such as wax benzenes and wax naphthalenes are recognized in the art as being particularly eifective detergents for mineral lubricating oils. The present invention is concerned with the provision of a new class of metal sulfonates, hereinafter called complex metal sulfonates, which have exceptionally high metal contents and which are highly superior oil detergents. The metal contents of these new complex metal detergent salts range from about 140 to about 180 per cent higher than that of the corresponding normal salts, i. e., salts having metal contents equivalent to the acid-hydrogen contents of the respective sulfonic acids from which they are derived.

t is the object of this invention to provide a new class of complex metal sulfonate salts having exceptionally high metal contents. It is a further object to provide oil compositions containing relatively small amounts of these salts, which compositions are of high detergent character. Other and further objects will become apparent from the following description of the invention.

Broadly, the complex metal salts of this invention are prepared by a method which comprises (1) intimately contacting an oil, or hydrocarbon, solution of a sulfonic acid, in the presence of water, with (a) at least about 1.6 equivalents of a metal hydroxide, (b) at least about 0.6 equivalent of a metal formate and (c) at least about 0.6 equivalent of a metal carboxylate, other than a metal formats, said equivalents being based on the equivalent of acid-hydrogen in the sulfonic acid solution, (2) substantially completely dehydrating the reaction mixture Patented Mar: 20, 1956 formed in step 1 to produce the complex metal salt product and (3) filtering off insoluble material.

A satisfactory procedure for carrying out the invention is as follows: An aqueous slurry of the three metalcontaining reagents is first prepared. This slurry is then intimately contacted with the sulfonic acid at a temperature of from about 25 Cup to about C. A diluent oil is required in the case of the synthetic type sulfonic acids in order to facilitate the reaction and the handling and filtration of the complex salt product. The synthetic sulfonic acids are, therefore, first dissolved in oil to form a solution of, say, from about 20 to about 60 per cent of the acid in the oil, this solution being contacted with the reagent slurry. The petroleum sulfonic acids are, of course, already diluted with oil, generally being present therein in amounts of from about 20 to about 60 per cent, and these acids, or sour oils, ordinarily require no addition of diluent oil for the purpose of the reaction with the metal-containing reagents. The contacting of the sulfonic acid (solution) with the reagent slurry is accomplished by slow addition of the slurry to the heated acid with constant stirring of the mixture thus formed. When the addition is completed, the mixture is dehydrated by raising the temperature up to about C. and maintaining this temperature until the dehydration is complete. The dehydrated product is then filtered to remove excess salt reagent. The product thus obtained is an oil solution which usually contains from about 20 to about 60-75 per cent, more or less, of the complex salt. It will be appreciated that in the case of the synthetic type sulfonic acids other hydrocarbon solvents may be used for the reaction besides mineral oil, such as a light naphtha, xylene, toluene or the like, however, use of a petroleum oil is preferred since it need not be removed after the reaction, the oil solution thus obtained being directly blendable with the lubricating oil desired to be fortified with the complex salt product.

Although the aforedescribed procedure is the one generally used, the manner and time of bringing the sulfonic acid solution and the metal compound reagents together may be varied Without affecting the reaction, or yield of complex salt product obtained. Thus, the sulfonic acid solution may be added to the reagent slurry or the sulfonic acid can be first reacted with the metal hydroxide and then reacted with an aqueous solution of the metal formate and metal carboxylate. Also, the normal metal sulfonate may be reacted with a slurry of all three reagents, the slurry containing the equivalent amounts of metal hydroxide, metal formate and metal carboxylate. This and other modifications of the procedure of the invention will be obvious to those skilled in the art. Several difierent procedures for carrying out the process of the invention are given in the illustrative examples hereinafter presented. In all cases, however, it is essential in our method that a good dispersion of the reactants be obtained, that water be present and the dehydration be carried essentially to completion. It is also necessary that certain specified amounts of the metal hydroxide, metal formate and metal carboxylate reagents be present in the reaction with the sulfonic acid in order to provide the complex salts of the invention. The metal formate and the metal carboxylate may be supplied in the form of a mixture of metal hydroxide with formic and carboxylic acids. For example, when the three reagents are supplied in the form of metal salts, at least about 1.6 equivalents of metal hydroxide, at least about 0.6 equivalent of metal formate and at least about 0.6 equivalent of metal carboxylate are required per equivalent of acid-hydrogen in the sulfonic acid solution utilized. Where the formic acid and carboxylic acid are supplied, as such, to the reaction, however, the amount of metal hydroxide used is increased enemas .3 toZZB-equivaIents in order to provide the necessary equivalents of metal in the reaction.

The necessity of the presence of water is illustrated by the fact that when dry calcium formate and calcium acetate areadded to an oil solution of a normalical'cium sulfonate and heated, subsequent analysis of the filtered oil shows no increase in the calcium contentthereof. In general, it may be said that an amount of water equal to at least about 25 per cent, by weight, of total metal salt. reagent utilized in the reaction is satisfactory. However, a larger amount of water may be used, the amount in each case 'being limited only by practical considerations, e. g, the type of sulfonic acid, the solubility of the metal salts, the feasibility of handling and length of time. to dehydrate the product, etc.

The necessity of dehydrating the reaction mixture is illustrated by the fact that if the reaction mixture is not substantially completely dehydrated, but only refluxed for a few hours, the oil' phase, when separated from the aque one phase, shows a metal content equal only to the normal metal sulfonate; The dehydration step has been con ducted under various conditions and it has been found that there is no'definite limitation on the method 'of dehydrating, except for practical considerations. Genorally, the-dehydration is accomplishedby heating at moderately elevated temperatures, i. e., from about 20 C'. toabout 120 C. for several hours. Although higher temperatures may be used, they are unnecessary. In those instances where the dehydration temperature reached 150 C., the metal content of the'products obtained was only slightly higher (0.1 per cent) than where the temperature remained below about 100 C The dehydration may be facilitated by blowing a gas, such as airor nitrogen, through the heated reaction mixture; It' is generally-preferred to filter the product at temperatures in the'neighborhood of 100 C. since this temperature is high enough to keepthe product quite fluid.

Due to the intricate nature of the complex metal salts thus produced, no chemical formula can be ascribedto them at this time. Neither is the manner of their formation precisely known. However, without intending to limit our invention by theoretical considerations, it is helievedthat our complex salts are formed via a two-step process in which the normal metal sulfonate is" first formed by" reaction with the metal hydroxide, the normal salt then being reacted further with the metal hydroxide-metal formate-metal carboxylate reagent during dehydration to yield the final product. salt during dehydration is postulated on the basis of certain-experimental observations. Thus, although anioil solut-i'on of complex metal sulfonate is obtainedby' interaction of a sulfonic acid with an aqueous solution of. metal formate' and metal acetate by substantially completely dehydrating the reaction mixture ('i'. e., removal ofat least about 90'per cent of the Water), if the oil phase is separated before such dehydration, the metal content corresponds only to that of anormal metal sulfonate: Also, indications of the formation of complexes between the. metal compound reagents during dehydrationiare'had' from X-ray difiraction examination of the solid material obtained on evaporating an aqueous solution of (a)- calcium formate-and calcium acetate and (b') calcium"hy-, droxide, calcium formate and calcium acetate; These analyses-show nopatterns that can be attributed to either calcium formate or calcium acetate, thus inferring. the formation of different compounds. Also, X-ray analysis of excess solid material isolated from a normal: calcium. sulfonate-calcium. formats-calcium, acetate reaction mixturewasfound tobeidentical to the aforementionedsolid: derived. from a water solution of the metal. formatewand metal acetate. Furthermore, it has been found that. more metal can be incorporated, into the sulfonate complex by usingamixture of metal acetate and metal formatethan by using, an equivalent amount of eitherv salt alone.v This. is believed to be due to the formation of an acetate- T he formation of the complex" formate complex. Finally, since the presence of an appreciable amount of water is necessary in order to form our complex salts, ionization is apparently an essential factor in their formation.

We are aware that certain complex metal sulfonate salts, somewhat similar in nature to the complex metal sulfonate salts herein contemplated, have been shown. heretofore in the grease art. Thus, several. patents, viz. Zimmer et al., No. 2,444,790, and OHalloran,. Nos. 2,553,422 and 2,562,814, disclose complex sulfonate salts. as gelling. agents. These salts are formed by reaction of normal sulfonate salts with a low molecular weight acid salt, such as metal acetate. Our complex salts are dis tinguished from the complex salts of these patents by virtue of the fact that these latter salts are oil-insoluble and provide grease-like structures in the oil, whereas our complex salts are oil-soluble. Only one carboxylate reagent salt is utilized in the preparation of the prior art salts whereas our complex salts are prepared from a com bination of a formate salt with another carboxylate salt. Our complex salts have much greater metal contents and are apparently of an entirely different configuration from those of the prior art. Accordingly, our complex salts are claimed herein as new compositions of matter.

The metal constituent of themetal hydroxide, metal formate and metal carboxylate (other than metal formate) reactants used in the preparation of our complex salts may be different metals, so that mixed metal complex salts, i. e., salts having more than a single metal constituent, may be successfully prepared and are contemplated herein. We have, in fact, prepared and tested complex salts containing two and three metal constituents and have found them to be highly effective detergents as shown in the examples presented hereinafter. Up tothe present time, our work has extended only to .the metal. salts. of those metals falling within group I and group II of the periodic table. However, it seems probable that reagent salts of other metals will also be found to be suitable'for the invention. We have found that complex metal salts of the metals of group II of the periodic system, particularly the calcium, barium and magnesium salts and the mixed salts of these metals, provide outstanding detergents' for lubricating oils.

The carboxylic acids, or salts thereof, suitable for the preparation of our complex metal salts are the aliphatic. carboxylic acids other than formic acid having up to about 20 carbon atoms in the aliphatic portion thereof. The acid. may be either saturated or unsaturated. It may. also contain certain substituent groups, such as phenyl, hydroxy, halogen, amino or mercapto groups. As non-limiting examples, there may be mentioned acetic acid", chloroacetic acid, phenylacetic acid, hydroxy acetic acid, glycine, thioglycollicv acid, acrylic acid, propionic acid, butyric acid, butenic acid, valeric acid, heptylic acid,-. caproic acid, lauric acid, myristic acid, palmitic acid, oleic. acid, stearic acid and the. like. The lower molecular weight acids, such. as acetic acid, are preferred. however, since they provide complex salts having the. higher proportions of metal per mol of complex salt.

Asaforesaid, the sulfonic acids suitable for use in. this invention include oil soluble petroleum sulfonicacidsand synthetic alkaryl sulfonic acids, particularly those having. higher molecular weights, i. e., from about. 300 to about 800. These sulfonic acids may be produced by sulfonation of petroleum stocks or synthetic alleyl. aromatic: compounds, such as alkyl-substitutedbenzenes or naphthalenes wherein the alkyl groups attached to the aromatic ring contain at least about 8 carbon'atoms, the wax-substituted benzenes and naphthalenes' beingparticul'arl'y" preferred. The petroleum sulfonic" acids; also known as sour oils, are those obtained in the treatment ofpetroleum. oils, particularly refined, or semi-refined oils, with concentrated or fuming sulfuric acid, and which remain. in. the oil after settling out of sludge... These assume" sulfonic acids may be represented by'the general for mula - pared from a furfural-refined East Texas stock (Stock TABLE I Properties I Stock A Stock B Kin. Vis. 100 F 82. 33 134. 4' Kin. Vis. 212 F 9. 30 12. 22 Viscosity Index. 97 85 Percent Sulfur 0. 23 0. 23 Spec. Gravity 0. 8833 0.8922 A. P. I Gravity 28. 7 27.1 Pour, F 20 20 Flash, F 435 490 Fire, F 495 530 Color, Lovibond- 38 42 Color, ASTM 5 7 Viscosity Gravity Constant at 210 F 0. 814 0. 822

TABLE II Sour Oil Treat No.

Total N. N 24.1 33. o 32. 1 29. 9 True N- N 19. 6 28. 1 26. 3 22. 9 Kin. V1s.@ 210 F 29. 48 28. 91 26. 6 Benzene Iusolubles 0. 07 1. 9 1. 8

EXAMPLE 1 Preparation of Sour Oil Treat 183 Thirty per cent by weight of 103 to 104% sulfuric acid was added over a period of 36. hour to an air-agitated charge oil (East Texas heavy waxy neutral), the reaction mixture being maintained at 90 to 135 F. Quench water (6 per cent by weight of charge oil) was then added over a /2-hour period at a temperature of 115 to 150 5., followed by a 20-hour settling period at 160 F. The sludge and spent acid were withdrawn, and the product blown with air for 2 hour at 160 F. to remove the occluded sulfur dioxide. A final settling period of 21 hours at 160 F. was carried out to insure as complete a removal as possible of spent acid and sludge. product had a total N. N. of 33.0 and a true N. N. of 28.1 and was obtained in a yield of about 97 per cent by weight'of the oil charged. The total N. N. designates the combined acidity of the sulfonic acid and residual sulfuric acid in the sour oil, while the true N. N. designates the acidity due to the sulfonic acid alone.

Preparation of calcium-f0rmate-acetate-sulf0nate complex In the following examples, procedures for the preparation of complex calcium sulfonate salts of the character contemplated by this invention are given in order to illustrate various aspects and modifications of the invention. The amounts of reagents, i. e., calcium hydroxide, calcium formate and calcium acetate utilized in Examples 2-6 are based on the total acidity of the sour oil, which, as aforesaid, includes minor amounts of free sulfuric acid present therein. Calculations on the amount The final of calciumincorporated into the final product were based on the true acidity, a measure of the organic snlfonic acids present inthe sour oil and are expressed in terms of the percentage excess calcium over the theoretical value for the normal calcium sulfonate.

EXAMPLE 2 Four hundred grams of Sour Oil Treat 162 were placed in a 1-liter, four-necked, round-bottom flask equipped with a mechanical stirrer, thermometer, air inlet tube, reflux condenser and dropping funnel. The sour oil was heated with stirring and a moderate stream of air passing through it to approximately C.

A reagent slurry, prepared by adding a solution of 4.7

grams (0.6 equivalent based on total acidity) of 98 per cent formic-acid and 6.6 grams (0.6 equivalent) glacial acetic acid'in a 50 ml. water to a slurry of 18.5 grams (2.8 equivalents) grease makers lime (96 per cent calcium hydroxide) in 50 ml. water, was then added slowly to the sour oil over a one-hour period from a dropping funnel while maintaining the reaction temperature at 70-75 C. The slurry was stirred from time to time to assure homogeneity. An additional 25 m1. of water was used to complete the transfer of reagents to the reaction mixture. When the addition of the reagent slurry to the sour oil was complete, the heat was increased and the water removed by means of a Dean-Stark take-off. The dehydration was completed in about 1 /2 hours with the temperature being regulated so as not to exceed about C. The temperature was maintained for an additional hour after all the water was apparently removed in order to insure complete dryness. Sixteen grams (4 per cent by weight of sour oil) of Hyfio (a diatomaceous earth filter aid) were then added with stirring and the product filtered through an electrically heated Biichner funnel using filter paper precoated with Hyflo, under a vacuum of approximately 150 mm. and a temperature of 80-100 C. The product filtered in about 45 minutes yielding 385 grams of a bright, brownish red oil.

Analysis of product:

Per cent calcium=l.7 8 (140 per cent in excess of normal salt). Per cent sulfur=1.23 Kin. vis. 210 F.=23.35

The complex calcium petroleum sulfonates may also be prepared by adding the sour oil to the reagent slurry. This procedure is illustrated by Example 3.

EXAMPLE 3 Four hundred grams of Sour Oil Treat 183 were added over a one-hour period to a mechanically agitated and air-blown slurry containing ml. water, 25.4 grams (2.8 equivalents based on total acidity) of grease makers lime, 713 grams (0.6 equivalent) 88 per cent formic acid and 8.5 grams (0.6 equivalent) glacial acetic acid. The temperature of the reaction mixture was maintained at 65 -75 C. during the addition. The dehydration was effected by gradually heating the reaction mixture to 115 C. while removing the water with a Dean-Stark take-ofi. To insure the complete removal of occluded water, the temperature was maintained at 115 C. for one hour. The filtration was carried out by stirring into the product 16 grams (4 percent by weight of sour oil charge) of Hyllo filter aid and filtering the mixture through an electrically heated B'tichner funnel using filter paper precoated with Hyfio.

Analysis of product:

Per cent calcium- 2.39 per cent in excess of normal salt).

The reactants can also be combined by first neutralizing the sour oil with calcium hydroxide and then adding an aqueous solution of calcium formate and calcium acetate. The latter salts may either be preformed or pli hed by adding; a slurry of; calcium. hydroxide. to the:

sounoil asin .Ex.amp1e 4, OrinverseIy; adding-' the soi oil to the calcium hydroxideslurry -as;in Example 5;

EXAMPLE 4- Four hundred-grams of SourOil Treat 189 were placed in a 1-liter, four-necked, round bottom flask fitted: with a mechanical stirrer, thermometer, air-inlet tube, reflux condenser and-addition funnel; The sour oil was heated, with stirring and with a moderate stream of air passing through it, to approximately 75 C. A slurry of 14.2 grams (1.6 equivalents based on total acidity) of grease makers lime in 75 ml'. waterwas then added over aone-hour period in small increments through the dropp'ing'funnel; 'Ihis-was-followed by-a ml. Water wash to complete; the transfer of the slurry, and then by a dropwise addition of a solution containing 8.9 grams (0.6 equivalent) ofcalcium formate and 12.0 grams (0.6 equivalent) of calcium acetate monohydrate in 100 ml. water over a one-hour period at -75 C. The dehydration was effected by gradually heating the reaction mixture to 115 C. while removing the water with a Dean-Stark take-oft. To insure the complete removal of occluded water, the temperature was maintained at 115 C. for one hour. The filtration was carried out by stirring into the product 16 grams (4 per cent by weight of the sour oil charge) of Hyfio filter aid and filtering this mixture through an electrically heated Biichner funnel using filter paper precoated with Hyflo.

Analysis of product:

Per cent calcium=2.58 (160 per cent v in .excess' of normal salt). Per cent sulfur=l.59 Kin. vis. @v 210 F.=56.78

EXAMPLE 5 A slurry of 14.1 grams (1.6 equivalents based on totalacidity) ofgrease makers lime. in 1.00 ml. water was charged into a 1-liter, four-necked, round-bottom flask equipped with a mechanical stirrer, thermometer, air inlet tube, dropping funnel and; reflux condenserand heated with stirring and moderate air blowing to approximately C. Four hundred grams of Sour Oil Treat 189 were added through the dropping funnel over a two-hour period with the reaction temperature being maintained at approximately 75 C. The resulting mixture was then heated at C. for one-half, hour after which a solution prepared by the reaction of 6.5 grams (0.6 equivalent) 98 per cent formic acid, 8.3 grams (0.6 equiv alent) glacial acetic acid and 10.5 grams (1.2 equivalents) grease makers lime in 100 ml. water was added dropwise over a one-hour period at about 75 C. The dehydration was effected'by. gradually heating the reac-- tion mixture to C. while removing the water with, a Dean-Stark take-off. To insure the complete removal of occluded water, the temperature was maintained at 115 C. for one hour. The filtration was carried out by stirring into the product 16 grams (4 per cent by weight of sour oil charged) of H yflo filter aid and filtering thismixturethrough an electricallyheated Biichner funnel using filter paper precoated with Hyflo.

Analysis, of product:

Per cent calcium=2.47 per cent in excess of normal salt). Per cent sulfur=l.46 Kin. vis. 210 F.=52.57

t not s es ar m s a. u f n a i a he star an aqueous slurrycontaining equivalentamounts of cal.-

PSI

uin hydroxi e. lpi mfor na-te nd cak wtateo yield a complex salt.

Four hundred grams-of, a, normal, calcium petroleum sulfonate prepared by the neutralization of Sour Oil Treat 193 and containing 0.86 per cent calcium was charged intoa, ll-liter, four necked; round-bottom flask ually heating the reaction mixture to 115 C. while removing the water with a Dean-Starktake-off. To in surethecomplete. removal of occluded=water; the tern perature was maintained at 11 5 C. for one hour. The filtration was. carried out by stirring intothe product 16 grams. (4 per cent by weight of sulfonate charged) of Hyilo? filter aid and filtering this mixture through an electrically heated Biichner funnel using filter paper pre+ coated with Hyflo."

Analysis of, product:

Per cent calcium=2 .40 (1 80 per cent in excess of? normal salt).

Per cent sulfur=1;42

Kin. vis. 210? F.=48.37

Potentiometric base No.=,47

A typical synthetic alkyharylsulfonic acid, viz., waxbenzene (2-1-2) sulfonic acid was prepared as shown in the following example.

EXAMPLE 7 Preparationl of wax-benzene (2-12) sulfonic acid with a stirrer, reflux. condenser. and athermomcter. Th

mixturev was heated to atemperature of 60 C. Alu-l minum chloridewas then added slowly over a period; of 1 two hours.

o fr80 C a nd. held therefor one hour. The excess;benzenewasthen removed .byinverting the reflux condenser.

andheating toa temperature of 116 C. Twohundred:

milliliters, of benzene were thus recovered. .Thflfll'llXf turewas cooled, to a temperature of 60 C. and-then another- 1000:grams of'pchlorowax were-added. slowly.v After: completing theaddition of this. chlorowax, thetemperaturewas-raised to 100- C. and held there-for one.

hour. The product was allowed: tostandiovernight at a temperature of about 60 C,, and then was separated. from-the sludge by decantation and filtered by suction throughclay'. i I

Seventeen hundred and thirty-eightgrams' of-Wax-bemzene;thus obtained were. placed in'a I i-necked flask" equippfld with a stirrer and a thermometer andheated" to a, temperature-of 40? C. Eight'hundred' and sixty-= nine grams ofz'oleum (15"per-cent SOs.) were'addedslowly to the .wax;benzene fromra dropping funnelrat.afirateregu lated 'to maintain the temperature. below. 50 .C; The: addition of; oleurn consumed aboutB-hours. 'Eiie mixture':

The addition of aluminum chloride; was: accompanied by a vigorous, evolution ofihydrogen chloride. The temperature. wasgthen raised to a temperature:

was then stirred for an additional hour to ensure complete reaction. The mixture was then poured into 1000 milliliters of water and subsequently 1810 grams of mineral oil were added to the mixture. obtained was stirred thoroughly and then allowed to stand until the water separated into a layer. The water layerwas then drained ed. The product thus obtained was approximately a 50 per cent blend of wax-benzene sulfonic acid in mineral oil and had a neutralization num ber of 40.7.

It will be understood that a wax-benzene prepared ac.

cording to the foregoing procedure in which a quantity of chlorowax containing 2 atomic proportions of chlorine and having a chlorine content of 12 per cent is reacted with 1 mol of benzene is designated wax-benzene (2-12)." Similarly, wax-benzene (3-10) and waxbenzene (1-10). may'also be prepared by the reaction of sufiicient. amounts of chlorinated wax, containing per centvby weight of chlorine, to provide 3 atomic pro portions and 1 atomic proportion of chlorine per mol of benzene, respectively, in the reaction and are useful in the invention. In general, the amount of chlorowax containing from about 10 to about 18 per cent by weight of chlorine used in the reaction is sufiicient to supply between 1 and 4 atomic proportions of chlorine per mol of benzene used.

EXAMPLE 8 Preparation of complex formate-acetate calcium waxbenzene (2-12) sulfonate Four hundred grams of wax-benzene (2-12) sulfonic acid, prepared in the manner of Example 7, and 150 grams of mineral oil (SUV of 100 sec. 100 F. acid-refined Mid-Continent) were charged into a 1-liter, four-necked, round-bottom flask equipped with a mechanical stirrer, air inlet tube, thermometer, reflux condenser and dropping funnel. The solution was heated with stirring and with a moderate stream of air passing through it toapproximately 75 C. A slurry prepared by intermixing 35.1 grams (2.8 equivalents based on total acidity) grease makers lime, 9.3 grams (0.6 equivalent) 98 per cent acetic acid and 11.8 grams (0.6 equivalent) glacial formic acid in 150 ml. water was added dropwise over a onehour period. Dehydration was eifected by gradually heating the reaction mixture to 115 C. for one hour. The

The mixture thus filtration was carried out by stirring into the product 22 grams (4 per cent by weight of sour oil charged) of Hyflo filter aid and filtering the mixture through an electrically heated'Biichner funnel using filter paper precoated with Hyflo.

Analysis of product:

Per cent calcium=2.58 (120 per cent in excess of normal salt). Per cent sulfur=l.80 Kin. vis. 210 F.=13.90 Potentiometric base No.=36

EXAMPLES 9-18 As stated hereinbefore, we have found that the use of about 1.6 equivalents of metal hydroxide, about 0.6 equivalent of metal formate and about 0.6 equivalent of the metal carboxylate, other than metal formate, provide the i '16 obtained in aseries of preparations of a calcium format acetate-sulfonate complex salt utilizing varying amounts of the reagent salts fo'r'reaction with Sour Oil Treat 183. It will be'observed that variations from the preferred amounts of reagents for the most part caused a decrease in the calcium content of the final product and that where increases in the metal content of the complex salt were obtained suchincreases Were not in proportion to the increase in calcium content of reagent used. The procedure used in all cases was that described in Example 2. Generally, the preferred proportions found for the calcium reagents'are also applicable to the reagent saltsof theother .metals contemplated herein, however, we have found that some variation from these proportions in certain instances and in the case of certain metals provides products of higher metal content. Although in such instances, the use of the higher amounts of reagents usually cause difiiculty in the filtration of the product, such variation in the amounts of reagents are deemed to be within the scope'of our invention. Also, as aforesaid, some variation in the amount of metal salt reagent must be permitted depending upon the residual sulfuric acid content of the particular sulfonic acid utilized. The amounts ofthe'reagent' salts designated herein, therefore, actually represent about the least amounts which may be utilized for the successful preparation of the complex salt 'products having the high metal content contemplated herein, but are not the exact amounts and all cases.

Various grades of lime, such as grease makers lime, Bell-Mine chemical grade hydrated lime and chemically pure lime, may be used in preparing the complex calcium, salts of this invention. However, grease makers to be used in any lime is preferred because of its high purity, smallparticle size and its property of being wet by oil.

0 Engine evaluation "trated in Example 4. This product gave the following analysisbest results in the preparation of our complex metal salts,

these amounts being based on the acid-hydrogen value of the crude sulfonic acid, i. e., the total N.N. It is to be understood, however, that these proportions may vary somewhat depending upon the residual sulfuric acid content of the particular sour oil or synthetic sulfonic acid used. This sulfuric acid content may vary in amount from about several per cent to 20-30 per cent of the total acid content in difierent sour oils and for the obtainment of optimum results the metal formate and carboxylate reagents can be varied proportionately i. e., they may be decreased with an increase in the sulfuric acid value and vice versa. Table III shows the results Analysis of product: v

Per cent calcium=2 '.38 (165 per cent in excess of normal salt)i Kin. vis. 210 F.=49.5 Potentiometric base No.='34

Lauson D-4A detergency test gine with splash lubrication and having copper-lead bearings is used. The operating conditions are as follows:

Oil temperature F 225 Jacket temperature F 275 Speed R. P. M..- 1825 Brake load "H. P 1.6

One-half throttle.

13-1 air-fuel ratio.

Oil added every 20 hours The engine is inspected at the end of 20, 60 and hours,

(one-gallon sample used).

11 hezdura ion: of: h test. b in 0.0- ho s. :Thmfi el: sed: a. controlled- Mpb le s spe a type blend, gas ine (4. per. ce thermal p r. cent. catelsit qa ly e keel 1: 0am: sen -s r igh un. +2- cc. EL/saw- Diesel ("D-21') delergency'test Is s-es e r i a e fies e s or t e were... oil; in. preventing piston deposits and. top. ringwear, 7

A single cylinder CFR, 4,-cycle, supencharged diesel The duration ofthe test is 60;hours. The'fuel used' is' -a No. 2 fuel oilcontaining l per centsulfur. The resultsare reported in terms of' piston cleanliness; ratings as -in theDe l test. 1

TABLE ILL-PREPARATION on OAIJCIUM FORMATEmGETATE-SULFONATEEO GRAMS soon OIL TREAT 13a (TOTALYN. N.-=se .o. TRUE N.'N

EXAMPLES: -31

YA.SCI'iCSI'O both bimetallic and trimetallic complex mlfonates were also prepared (Examples 25-31). The 'datm' concerning their preparation their. inspection'andflheir ratings: in the CFR diesel D.-2"1' detergency test are:giVen= imTableVII.

EXAMPLES 32-42 'As' stated previously herein, it is possible to replace.- the metal acetate reactant-with substituted acetate'or'other carboxylate type salts in the preparation of'tlie complex salts of theinvention. A numberof such preparations? are illustrated by Examples 311-395 in Table Miii tures of twosuch salts (or acids may also be OMP2lE)x SALT USING 400' Reagents(With 125. ml. Water); Analysis of Product Example, iggfgggw 9s%noo on Glacial 011,00 on I 1 P t Potent) I gg fi y Percent gg ga metric .E 1 Ca Ca BTotlaIl we, g. Egg 7 we, g. gg I we, .8. I gg g 1009s.: 210 a.

25. 4 2. 8' 616 U. 6- 81 0. 6 23 39 58.18 24. 0 2. 6 6. 6 O. 6 I 8 0. 6 2.: 25 61-40 33; 8 3: 75 6. 6 0. 6 0. 6 2. 39 53142 36. O 3. 9 6. 6" 0.16 8 0. 6i 1 2. 51.61 25. 4 2. 8 8. 0 0. 7 10. 2' 0. 7 2,-38 62. 67.1 27. 7 3. 0 8. 0' O. 7 1D. 2 0. 7 2; I 53. 98", 30. 0 3. 2 8. 0 0. 7 10. 2 0. 7 2'. 47" i 63. 94 2a. 1 2. s a. 2 o. 4 6. 6 0. 45 2. 14 1 5s. 70. 25.4 2.8 3.3 0.3 v 12.7 0.9 1.89 41.44, 25. 4 2. 8 9.9 0. 9' 4. 2 0. 3 2524i I 42.73

TABLE-IVrCF-R DIESEL (D-21) TEST ON CALCIUM-FORMATEMDETA'IEESULFONATE COMPLEX OER Diesel Test'(1.0%'S.

Description of Detergent" Fuel) Oil 3 +13% Antioxidant l m- .1 E u valents of Reagents 1 Percent v Percent 1322:? Percent fllea li SulionieAcid 5 0 Excess in ess a v .Oa, Ca 2 gent in on lug-M160.

- None 62...

Petroleum Treat: 162 0. 6 1. 69 3. 5 0. 058

Wax-Benzene (2-12) ,0. 6 0. 6 2. 58 2. 2 0.058 85.

! Pet equivalent of sulfonie acid, pa sed on total N N. 2 Over that required for normal s I S. A. E. 30 grade solvent-refined Midflontinent oil. 4 Pinene-PzSs product.

TAB-LE V.-LAUS.ON 114a) TESLIf0N. CALCIUMfEORMA'IE-ACE'IATE-SULFONATE COMRLEX Description otzDetergentifg Pggiggggg f li Equivalents of'Reagents' Percent Oleanli :0 S1 A K PBICQBF- Dter- E E nes5' Rat--. 193 9. 01 Ga. gent; m. y mg.at.100.

Lime 02.01000): Ca'(CH':COO)1 I Oil Hours None 59" Petroleum..- 2.8 '0. 6i 1 0.6 2:38 2.74 0.058. 761-; do 2.,8 0.6 0.0 2.38, .165 3.7 0.088 as Per equivalent of sulfonicacid; based-on total N; N. =-Over that required fonnormal salt.

EXAMPLES 19-24 Anumber of. metal c mplex Saltsof.metals'g othergthan.. calcium which we have prepared are shown in: Table VI;

Examples 40.-142=,.Table;IX; illustrate: this typerofepmda-- use. Ther resul-tsaoirGFRzdiesehengine Drlledetengency-i testsaconduotedkoneoikbl'ends ofijtheieompleie salt products:

Thetable-shows the modeof-preparatiom and the-analyses: 75; thusnobtainedvareeineludedr;in therrespectivegtablese TABLE IL-PREPARATION OF COMPLEX FORMATE ACETATE SULFONATES OTHER TITAITC'ALCIUM AND THE1R ENGINE EVALUATION Description of Procedure 6 Exlaarmple Sulfonic Acid Hydroxide Formats Acetate 0.

Total True Wt. Wt. wt Treat N N N. (g) (g) Eqmv. (g) Equiv (g.) Equlv 33.0 28.1 160' Mg(OH)1 19.5 '2'6' 1100061199 75: "if? ""116 'iiiia''d'diigiilbiiiII"5f; "0.6 45.6 43.0 400 Mg(OH)4 25.4 2.3 HCOOH(98%) 9.2 0.6 03300011 1 61111. 11.7 0.6

29.9 22.9 300 1.6 31 HOOO)1-..- 22.7 0.6 Sr(CH1COQ)2.%H4O.- 27.2 0.6 32.1 26.3 400 2.6 H OOH (98%) 6.4 0.6 CBCOOH (glacial)- 8.2 0.0 29.9 22.9 300 1.5 HCOOK 21.4 0.6 011100012-.-- 25.0 0.6

script! CFR Diesel Test (D921) (19' s F1181) magma Analysis 011 8 +10% 21111611116116 1 Example No. Metal Potenti- Pwwa- Y $5151 1111312231 111551 11211312 2? Percent P616516 8 Base 1 1011 111011 60 Hours Excess No.

None 02 19 2 1.55 155 1.34 63.19 23 2.3 0.036 33 20 4 1.99 120 2.32 90.1 46 1.8 0.036 32 21 2 7. 120 1. 67. 71 2. 7 0. 20 34 22 4 3.51 1.55 37.20 20 3.6 0.13 33 23 2 3.69 1.59 67.8 27 2.6 0.096 61, 24 4 3.0 100 1.34 41.4 22 3.9 0.12 33 1 Equivalent to 0.2% barium.

i S. A. E. 30 grade solvent-refined Mid-Continent oil (kin. vi:

8 Pinene-P1S5 reaction product.

TABLE VIL-PREPARATION OF BI AND TRI METALLIC COMPLEX ACETA ENGINE EVALUATION 100 F. -121, kin. V13. 210 F.=12.2).

TE-FORMATE-SULFONATEB AND THEIR Description of Procedure Exfimple Sulfonic Acid Hydroxide Fol-mate Acetate Total True Wt. Wt Wt Wt Treat N'N. (g') (g) Equiv. Equlv. (g) Equiv 29.9 22.9 800 Ca(OH)2 (967) 1.6 Mg(HCOO)1 14.6 0.6 29.9 22.9 800 Mg(OH)2. 1.6 Ca(HCOO):- 16.6 0.6 29.9 22.9 800 1.6 Ca(HCOO)1- 16.6 0.6 32.1 26.3 400 1.6 Ca(HCOOg2- 8.9 0.6 29.9 22.9 800 1.6 Be(HCOO 2.- 28.9 0.6 29.9 22.9 800 1.6 Ca(HCOO)z 16.6 0.6 22.6 17.2 800 1.6 CB(HCOO)1- 12.4 0.6

Description OFR Diesel (D-21) (1% S 01 Proce- Analysis Fuel) OHM-1.0% Antldure oxidant:

Example N0. P t a Percent 0 an Percent Cleanlinese Prepara- Percent Excess Percent K. V. metri D o etergent Rating At tion Metal Metal 8 210 F. Totltgoliiase In on 60 Hours Non 62 25 Example Ca=1.07 135 1.32 46.6 33 3.2 87

. Mg=0.46 2 do Mg= 0. 98 156 1. 38 56. 5 36 2. 9 84 Ca==0.38 27 do Mg-O. 61 1. 46 49. 9 36 2. 9 .86

Ca=0.96 28 H0 Ba==4.08 120 1.54 45.3 27 3.0 84

Ca -0.53 Mg=0.14 29 fi Oa=1.09 130 1.38 44.0 31 3.2 85

Mg==0.25 30 do Mg=-0. 65 166 1. 55 45. I5 30 3. 8 85 Ca=0.54 Ba==1.67 3 d6 Zn==1.38 -1.,22 3.4 82

l Metal in oil equivalent to 0.2% barium. S. A. E. 30 grade solvent refined Mid-C I Ifinene-PzSa reaction product.

ontlnent 011 (kin. v13. 100 R 121, kin. V18. 210 F.12-2) equipped with a mechanical stirrer, thermometer, air in let tube, reflux condenser and dropping funnel. The sour oil was heated with stirring and with a moderate stream of air passing through it to approximately 75 C. A slurry of 24.7 grams (2.8 equivalents based on total acidity) of grease makers lime in 75 ml. water was then added over a onehour period in small increments through the dropping funnel. This was followed by the dropwise addition over a one-hour period of a solution containing 6.5 grams (0.6 equivalent) 98 per cent formic acid and 13.0 grams (0.6 equivalent) chloroacetic acid in 100 ml. water. The dehydration was effected by gradually heaing the reaction mixture to 115 C. while removing the water with a Dean-Stark take-oil. To insure the complete removal of the Water, the temperature was maintained at 115 C. for one hour.

The filtration was carried out by stirring into the product 16 grams (4 per cent by weight of sour oil charged) of Hytlo filter aid and filtering this mixture through a heated Buchner funnel precoated with Hyfio.

Analysis of product:

Per cent calcium=2.39 (150 per cent in excess of normal salt). Per cent sulfur=l.67 Per cent chloride:l.05 Kin. vis. 210 F.=4-8.0 cs.

The amount of complex salt product utilized in a lubricating oil will depend upon the particular oil and the application for which it is designed. Generally, amounts ranging from about 0.1 up to about 20 weight per cent may be used, the usual amount being from about 0.5 to about weight per cent.

The complex salt products of this invention may be used in lubricating oil compositions containing other addition agents designed to improve the oil in different respects, e. g., antioxidants, extreme pressure agents, pour point depressants, viscosity index improvers, defoamants, etc.

Although the complex salts of this invention are intended primarily for use as lubricating oil additives, they are also adaptable for use in other applications, e. g., they find application in the manufacture of detergent soaps and are useful as dispersants and rust preventives. They may also be used as additives for cutting and textile oils.

Although the proportions and utility of certain specific representative complex salt products and oil compositions thereof have been described in detail herein, it is not intended that the invention be limited in any way thereby, but that it include such variations and procedures and such products and compositions as come within the spirit and scope of the accompanying claims.

We claim:

1. A complex metal salt of a hydrocarbon-soluble sultonic acid produced by the method which comprises the steps of (1) forming a mixture of a hydrocarbon solution of the sulfonic acid with water and a reagent combination which will provide in said mixture at least about 1.6 equivalents of a metal hydroxide, at least about 0.6 equivalent of a metal formate and at least about 0.6 equivalent of an aliphatic metal carboxylate, other than a metal formate, having up to about 20 carbon atoms in the aliphatic portion thereof; the equivalents of said metal hydroxide, metal formate and metal carboxylate being based on the total equivalents of acid-hydrogen present in said hydrocarbon solution of the sulfonic acid and the metal constituent of said metal hydroxide, metal formate and metal carboxylate being a metal selected from groups I and II of the periodic table of the elements, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering off insoluble material 2. A complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (l) intimately contacting an oil solution of the sulfonic wax-benzene sulfonic acid produced by the method which comprises the steps of (1) intimately contacting an oil solution of the wax-benzene sulfonic acid, in the presence of Water, with at least about 1.6 equivalents of calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium acetate, the equivalents of said calcium hydroxide, calcium formate and calcium acetate used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering ofi insoluble material.

4. A complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (1) intimately contacting an oil solution of the sulfonic acid, in the presence of water, with at least about 1.6 equivalents of calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium propionate, the equivalents of said calcium hydroxide, calcium formate and calcium propionate used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering oil insoluble material.

5. A complex metal salt of a petroleum sult'onic acid produced by the method which comprises the steps of (l) intimately contacting an oil solution of the sulfonic acid, in the presence of water, with at least about 2.8 equivalents of magnesium hydroxide, at least about 0.6 equivalent of formic acid and at least about 0.6 equivalent of acetic acid, the equivalents of said magnesium hydroxide, formic acid and acetic acid used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering ofl insoluble material.

6. A complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (l) intimately contacting an oil solution of the sulfonic acid, in the presence of water, with at least about 2.8 equivalents of barium hydroxide, at least about 0.6 equivalent of formic acid and at least about 0.6 equivalent of acetic acid, the equivalents of said barium hydroxide, formic acid and acetic acid used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering otf insoluble material.

7. A complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (1) intimately contacting an oil solution of the sulfonic acid with an aqueous reagent slurry containing at least about 1.6 equivalents of calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium acetate, the equivalents of said calcium hydroxide, calcium formate and calcium acetate used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering off insoluble material.

8. A complex metal salt of an oil-soluble synthetic 19 calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium acetate, the equivalents of said calcium hydroxide, calcium formate and calcium acetate used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering oif insoluble material.

9. A complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (l) intimately contacting an oil solution of the sulfonic acid with an aqueous reagent slurry containing at least about 1.6 equivalents of calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium propionate, the equivalents of said calcium hydroxide, calcium formate and calcium propionate used being based on the total equivalents of acidhydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering olf insoluble material.

10. A complex metal salt. of a petroleum sulfonic acid produced by the method which comprises the step of (1) intimately contacting an oil solution of the sulfonic acid with an aqueous reagent slurry containing at least about 2.8 equivalents of magnesium hydroxide, at least about 0.6 equivalent of formic acid and at least about 0.6 equivalent of acetic acid, the equivalents of said magnesium hydroxide, formic acid and acetic acid used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering oif insoluble material.

11. A complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (l) intimately contacting an oil solution of the sulfonic acid with an aqueous reagent slurry containing at least about 2.8 equivalents of barium hydroxide, about0.6 equivalent of formic acid and at least about 0.6 equivalent of acetic acid, the equivalents of said barium hydroxide, formic acid and acetic acid used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydratmg the reaction mixture formed in step 1 and (3) filtering E insoluble material.

12 A mineral lubricating oil containing a minor proportion, sufiicient to improve the detergent ability of said 011, of a complex metal salt of a hydrocarbon-soluble sulfonic acid produced by the method which comprises the steps of (1) forming a mixture of a hydrocarbon solutron of the sulfonic acid with Water and a reagent combmatlon which Will provide in said mixture at least about 1.6 equivalents of a metal hydroxide, at least about 0.6 equ valent of a metal formate and at least about 0.6 equivalent of an aliphatic metal carboxylate, other than a metal formate, having up to about 20 carbon atoms in the aliphatic portion thereof; the equivalents of said metal hydroxide, metal formate and metal carboxylate being based on the total equivalents of acid-hydrogen present in said hydrocarbon solution of the sulfonic acid and the metal constituent of said metal hydroxide, metal formate and metal carboxylate being a metal selected from groups I and II of the periodic table of the elements, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering off insoluble material.

13. A mineral lubricating oil containing a minor proportion, sutficient to improve the detergent ability of said oil, of a complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (1) intimately contacting an oil solution of the sulfonic acid, in the presence of water, with at least about 1.6 equivalents of calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium acetate, the equivalents of said calcium hydroxide, calcium formate and calcium acetate used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering ofi? insoluble material.

14. A mineral lubricating oil containing a minor proportion, sufficient to improve the detergent ability of said oil, of a complex metal salt of an oil-soluble synthetic wax-benzene sulfonic acid produced by the method which comprises the steps of (l) intimately contacting an oil solution of the wax-benzene sulfonic acid, in the presence of water, with at least about 1.6 equivalents of calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium acetate, the equivalents of said calcium hydroxide, calcium formate and calcium acetate used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering olf insoluble material.

15. A mineral lubricating oil containing a minor proportion, suflicient to improve the detergent ability of said oil, of a complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (l) intimately contacting an oil solution of the sulfonic acid, in the presence of water, with at least about 1.6 equivalents of calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium propionate, the equivalents of said calcium hydroxide, calcium formate and calcium propionate used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering oii insoluble material.

16. A mineral lubricating oil containing a minor proportion, sufiicient to improve the detergent ability of said oil, of a complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (l) intimately contacting an oil solution of the sulfonic acid, in the presence of Water, with at least about 2.8 equivalents of magnesium hydroxide, at least about 0.6 equivalent of formic acid and at least about 0.6 equivalent of acetic acid, the equivalents of said magnesium hydroxide, formic acid and acetic acid used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering oif insoluble material.

17. A mineral lubricating oil containing a minor proportion, sufiicient to improve the detergent ability of said oil, of a complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (1) intimately contacting an oil solution of the sulfonic acid, in the presence of water, with at least about 2.8 equivalents of barium hydroxide, at least about 0.6 equivalent of formic acid and at least about 0.6 equivalent of acetic acid, the equivalents of said barium hydroxide, formic acid and acetic acid used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering of? insoluble material.

18. A mineral lubricating oil containing a minor proportion, sufiicient to improve the detergent ability of said oil, or" a complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (1) intimately contacting an oil solution of the sulfonic acid with an aqueous reagent slurry containing at least about 1.6 equivalents of calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium acetate, the equivalents of said calcium hydroxide, calcium formate and calcium acetate used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering off insoluble material.

19. A mineral lubricating oil containing a minor proportion, sufiicient to improve the detergent ability of said oil, of a complex metal salt of an oil-soluble synthetic Wax-benzene sulfonic acid produced by the method which comprises the steps of 1) intimately contacting an oil solution of the Wax-benzene sulfonic acid with an aqueous reagent slurry containing at least about 1.6 equivalents of calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium acetate, the equivalents of said calcium hydroxide, calcium formate and calcium acetate used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering off insoluble material.

20 A mineral lubricating oil containing a minor proportion, sufi'icient to improve the detergent ability of said oil, of a complex metal salt of a petroleum sulfonic acid produced by the method Which comprises the steps of l) intimately contacting an oil solution of the sulfonic acid with an aqueous reagent slurry containing at least about 1.6 equivalents of calcium hydroxide, at least about 0.6 equivalent of calcium formate and at least about 0.6 equivalent of calcium propionate, the equivalents of said calcium hydroxide, calcium formate and calcium propionate used being based on the total equivalents of acidhydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering ofi insoluble material.

21. A mineral lubricating oil containing a minor proportion, suflicient to improve the detergent ability of said oil, of a complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (1) intimately contacting an oil solution of the sulfonic acid with an aqueous reagent slurry containing at least about 2.8 equivalents of magnesium hydroxide, at least about 0.6 equivalent of formic acid and at least about 0.6 equivalent of acetic acid, the equivalents of said magnesium hydroxide, formic acid and acetic acid used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering oft insoluble material.

22. A mineral lubricating oil containing a minor proportion, sufiicient to improve the detergent ability of said oil, of a complex metal salt of a petroleum sulfonic acid produced by the method which comprises the steps of (1) intimately contacting an oil solution of the sulfonic acid with an aqueous reagent slurry containing at least about 2.8 equivalents of barium hydroxide, at least about 0.6 equivalent of formic acid and at least about 0.6 equivalent of acetic acid, the equivalents of said barium hydroxide, formic acid and acetic acid used being based on the total equivalents of acid-hydrogen present in said oil solution of the sulfonic acid, (2) substantially completely dehydrating the reaction mixture formed in step 1 and (3) filtering off insoluble materialv References Cited in the file of this patent UNITED STATES PATENTS Re. 23,082 Zimmer Jan. 25, 1949 2,467,176 Zimmer Apr. 12, 1949 2,553,422 OHalloran May 15, 1951 2,585,520 Van Ess Feb. 12, 1952 

1. A COMPLEX METAL SALT OF A HYDROCARBON-SOLUBLE SULFONIC ACID PRODUCED BY THE METHOD WHICH COMPRISES THE STEPS OF (1) FORMING A MIXTURE OF HYDROCARBON SOLUTION OF THE SULFONIC ACID WITH WATER AND A REAGENT COMBINATION WHICH WILL PROVIDE IN SAID MIXTURE AT LEAST ABOUT 1.6 EQUIVALENT OF A METAL HYDROXIDE, AT LEAST ABOUT 0.6 EQUIVALENT OF A METAL FORMATE AND AT LEAST ABOUT 0.6 EQUIVALENT OF AN ALIPHATIC METAL CARBOXYLATE, OTHER THAN A METAL FORMATE, HAVING UP TO ABOUT 20 CARBON ATOMS IN THE ALIPHATIC PORTION THEREOF; THE EQUIVALENTS OF SAID METAL HYDROXIDE, METAL FORMATE AND METAL CARBOXYLATE BEING BASED ON THE TOTAL EQUIVALENTS OF ACID-HYDROGEN PRESENT IN SAID HYDROCARBON SOLUTION OF THE SULFONIC ACID AND THE METAL CONSTITUENT OF SAID METAL HYDROXIDE, METAL FORMATE AND METAL CARBOXYLATE BEING A METAL SELECTED FROM GROUPS I AND II OF THE PERIODIC TABLE OF THE ELEMENTS, (2) SUBSTANTIALLY COMPLETELY DEHYDRATING THE REACTION MIXTURE FORMED IN STEP 1 TO (3) FILTERING OFF INSOLUBLE MATERIAL. 